The effects of four different training protocols on upper body muscular strength and endurance development in untrained boys and girls were studied. Two training sessions per week for eight weeks were provided. Exercises included 10 strength exercises on child-size machines and concluded with medicine ball activities. The test task was the number of vertical chest passes that could be performed to volitional fatigue. The groups were:

G1 (N = 15) one set of 6-8 repetitions of strength exercises.

G2 (N = 12) one set of 6-8 repetitions of strength exercises followed by one set of 6-8 medicine ball chest passes.

G3 (N = 16) one set of 13-15 repetitions of strength exercises.

G4 (N = 11) performed one set of 13-15 repetitions of medicine ball chest passes.

Implication. If children are to perform one exercise set, repetitions should be relatively high (13-15), the load moderate, and the exercise completed to exhaustion. A combination of low repetitions and medicine ball work produces similar results.